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Full Discussion: Code explanation?
Top Forums UNIX for Dummies Questions & Answers Code explanation? Post 302583532 by ryran on Tuesday 20th of December 2011 03:34:52 PM
Old 12-20-2011
Quote:
Originally Posted by kotsos13
As i said before he didn't taught us the cut command and now i have to learn the code without cut Smilie
In this command how do i understand pulling out only the username and the uid?
I'm sorry man. I love sed, and I use it for all kinds of things, but I would never use it for this. ... I don't understand how it's being used here, and I don't quite care to try and muddle through it and figure it out, though I'd be curious to have someone explain it. If your uh... unorthodox.. instructor won't explain it to you (and no one else answers), you could try to puzzle through it with the help of the sed info page (type info sed).

As a consolation prize, here's a command that does the same thing your instructor's original command was supposed to do, but more simply and more efficient. Maybe he'll be impressed. Smilie
HTML Code:
awk -F: '/^[^:][^:][^:][^:]:/ {print $1" "$3}' /etc/passwd | sort -t' ' -k2 -nr
 

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LEARN ABOUT DEBIAN

qrencode

QRENCODE(1)						      General Commands Manual						       QRENCODE(1)

NAME

       qrencode - Encode input data in a QR Code and save as a PNG or EPS image.

SYNOPSIS

       qrencode [OPTION]...  [STRING]

DESCRIPTION

       Libqrencode  is	a  library  for encoding data in a QR Code symbol, a kind of 2D symbology that can be scanned by handy terminals such as a
       mobile phone with CCD. The capacity of QR Code is up to 7000 digits or 4000 characters, and has high robustness.

       Qrencode is a utility software using libqrencode to encode string data in a QR Code and save as a PNG or EPS image.

OPTIONS

       -h, --help
	      display help message.

       -o FILENAME, --output=FILENAME
	      write image to FILENAME. If '-' is specified, the result will be output to standard output. If -S is given, structured  symbols  are
	      written to FILENAME-01.png, FILENAME-02.png, ... (suffix is removed from FILENAME, if specified)

       -s NUMBER, --size=NUMBER
	      specify the size of dot (pixel). (default=3)

       -l {LMQH}, --level={LMQH}
	      specify error collectin level from L (lowest) to H (highest). (default=L)

       -v NUMBER, --symversion=NUMBER
	      specify the version of the symbol. (default=auto)

       -m NUMBER, --margin=NUMBER
	      specify the width of margin. (default=4)

       -d NUMBER, --dpi=NUMBER
	      specify the DPI of the generated PNG. (default=72)

       -t {PNG,EPS,ANSI,ANSI256}, --type={PNG,EPS,ANSI,ANSI256}
	      specify the type of the generated image. (default=PNG)

       -S, --structured
	      make structured symbols. Version must be specified.

       -k, --kanji
	      assume that the input text contains kanji (shift-jis).

       -c, --casesensitive
	      encode lower-case alphabet characters in 8-bit mode. (default)

       -i, --ignorecase
	      ignore case distinctions and use only upper-case characters.

       -8, --8bit
	      encode entire data in 8-bit mode. -k, -c and -i will be ignored.

       -M, --micro
	      encode in a Micro QR Code. (experimental)

       -V, --version
	      display the version number and copyrights of the qrencode.

       [STRING]
	      input data. If it is not specified, data will be taken from standard input.

EXAMPLES

       qrencode -l L -v 1 -o output.png 'Hello, world!'
	      encode into a symbol version 1, level L.

       qrencode -iSv 1 --output=output.png
	      read standard input and encode it into a structured-appended symbols in case-insensitive mode.

AUTHOR

       Written by Kentaro Fukuchi.

RESOURCES

       Main Web Site: http://fukuchi.org/works/qrencode/

       Source code repository: https://github.com/fukuchi/libqrencode/

COPYRIGHT

       Copyright (C) 2006-2012 Kentaro Fukuchi.

qrencode 3.3.0							   Feb. 29, 2012						       QRENCODE(1)
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